fix blocking function call spec in ffi
[Truffle] Use BigInteger#equals instead of compareTo when possible.
[Truffle] Implement Kernel#to_s for all objects and use it in ToSNode.

* Fix fallback to use Kernel#to_s on object, not its class.
* Use the lazy pattern for the kernelToSNode since it should be rarely used.
[Truffle] Prune language tags.

$ ruby spec/mspec/bin/mspec tag --purge --config spec/truffle/truffle.mspec spec/ruby/language -t /path/to/ruby-trunk
[Truffle] Very basic keyword arguments.
Merge pull request #2303 from tduehr/ffi_spec_change

fix blocking function call spec in ffi
Make sleep interrupts more robust by using Semaphore.
[Truffle] Partial implementation of Array#reject.
[Truffle] Untagged passing spec now that Array#reject works.
Removed unused RubyEncoding factories.
Removed a bunch of unused, deprecated RubyEncoding methods.
Fixes #2172: Symbols need to support UTF-8 names
[Truffle] Use a generated method instead of using directly the specialization.
Fix time comparison in blocking FFI call spec.
Removed unused constructors.
[Truffle] More work on keyword arguments.
[Truffle] More work on keyword arguments - a bit rough in places but works.
Merge branch 'master' into truffle-head

Conflicts:
	core/src/main/java/org/jruby/truffle/runtime/core/RubyBignum.java
	spec/truffle/tags/language/method_tags.txt